5 Soil Heath Case Studies
This project aims to provide a better regional understanding of the impact of the alternative and chemical fertilisers on soil moisture holding capacity, growing season length, soil acidity and other soil health parameters such as microbial properties (mainly bacteria and fungi), organic and pasture production.
The methods are used: Five paired case study sites on farmer properties measuring soil health (paired means one site has a soil health or chemical treatment and the other a control). The treatments here have been established for a minimum of five years. It is important to note that the paired site is either a different paddock on the same farm or a different farm (next door). All paddocks are adjacent to their comparison. Care was taken to choose similar pasture species and soil types, but the grazing management was not the same and soil health treatments also different.
There was a range of grazing strategies and this influenced soil health and plant available water. The soil health was generally better where there were alternative fertilisers, however the soil health was well supported where there was a high grazing pressure and low grazing days. The soil biology was not as good where there was low ground cover and less plant species diversity.
The cation exchange capacity (CEC) was always higher on the biological sites supporting the transfer of nutrients from the soil to the plant. Denitrification was higher on high chemical N input sites. The pH of the soil was better in biological side irrespective of liming treatment.
The report highlights the importance of grazing management, ground cover, and mix of pasture species in conjunction with biological fertilisers to support soil health.
The final report needs a few small final edits pending feedback from the case study farmers and can be found here